Universal screw head



United States .Patent O 3,269,250 UNIVERSAL SCREW HEAD Lawrence M.Curtiss, Mountainside, NJ., assignor to The Thomas & Betts Co.,Elizabeth, NJ., a corporation of New Jersey Filed July 2, 1964, Ser. No.379,993 4 Claims. (Cl. 85-45) The present invention relates to thread'edfasteners generally and more particularly to a universal head forscrews, bolts and the like of various kinds having a subsantially flatFillister like head portion with a cavity and cross slots recessedtherein.

More specifically, the invention relates to screws generally which areprovided with a cross slotted driving recess in .the head thereof,whereby to selectively accommodate each of several conventional d-rivinginstrumentalities therein, the invention residing in the additionthereto of integral means for guiding or deflecting the working end of awinged driving tool into its recess, and a bladed tool into alignmentwith one or both of said slots in said screw head when brought intoContacting relation th'erewith.

Prior art screw heads of this character while considered satisfactory inmany applications possessed particular disadvantages in thatconsiderable `difliculty was often experienced in quickly aligning andinserting a single or crossbladed driving tool into one or both of apair of intersecting slots in such screw heads particularly when thesc-rews are part of small electrical fittings, for example, whichfittings are often used in junction boxes and other close and/ordifficult quarters where a clear and full sight approach to a set screw,for example, cannot be had. Thus, a screw head which avoids or greatlyreduces such difiiculties in the manipulation thereof is highlydesirable and useful.

Accordingly, it is an object of the invention to provide an improvedcross-slotted and/or axially recessed screw head which is adapted forautomatically angularly deflecting a conventional driving tool intocentral alignment with 'either one or both of said cross slots whenbrought into contact with said screw head.

A further object of the invention is to provide an improved crossslotted and/ or axially indented flat Fillister type screw head which isadapted to be .readily engaged and actuated by either one of severalconventional screw drivers of compatible size as for example, a singleblade, cross blade, pointed, winged Phillips type, or a driving toolhaving a flat ended square shank.

Another object of the invention is to provide an improved cross slottedand/or axially recessed Fillister type screw head in the use of which anoperator need only point a selected driving tool to the approximatecenter thereof and the tool moved into coactable contacting relationtherewith, whereby the driving tool is automatically centered andoriented into alignment with and guided into either one or both of saidcross slots and a recess in the intersection thereof.

With the above and other objects in View, the invention resides in thenovel construction, combination, and arrangement of elements, the novelfeatures of which are set forth with particularity in the appendedclaims, the invention itself, however, both as to the combinationtherein and method of operation together with additional objects andadvantages thereof, being best understood from the following descriptionof a specific embodiment thereof, when taken in connection with theaccompanyng drawing in which:

FIGURE 1 is a perspective vi'ew showing a Fillister type of screw headas provided with a pair of cross slots, a cavity formed in the slotintersection on the screw axis,

3,209,250 Patented August 30, 1966 ice and a pair of oppositely inclinedflat surfaces formed on each of the angularly spaced head portionsformed by said intersecting slots in accordance with .the invention;

FIGURE 2 is a top plan view of the same;

FIGURE 3 is a Sectional view taken on the line 3-3 of FIGURE 2; andFIGURE 4 is a similar Sectional View illustrating a modification of thescrew head in FIGURE 3.

Referring to the drawing, a screw head formed in accordance with theinvention is indicated at 10 in which a pair of lrectangular slots 12and 14 are formed in inters'ecting relation and substantially at rightangles on the screw axis. Both of the intersecting slots are identical,of the same depth, and both extending diametrically across the entirediameter of the screw head 10, which is straight and of substantiallyuniform diameter and of la length proportional to the threaded shank 16`of the screw after the manner of conventional flat head Fillister typemachine screws. The side walls of the slots 12 and 14 are parallelrespectively Ithroughout their entire extent and are slightly inclinedor diverge outwardly from the bottom thereof to their upper definingedge to readily receive tapered single blade screw drivers.

The bottom of the slots 12 and 14 are flat surfac'es, all of which liein the same surface of lrevolution except for a center clearance cavityor indentation 18. The center cavity 18 is in the form of an invertedcone with a rounded a-pex 20 located on the screw axis with th'ediameter at the top of the cavity slightly larger than the width of theslots as clearly shown in FIGURES l and 2.

It will be noted that the intersecting slots form a plurality -ofdiametrically opposite, angularly spaced triangular head portions orsegments 22 with their inner corner portions 24, disposed radially ofthe screw axis and projecting substantially over or into the cavity 18,whereby they are adapted for driving engagement with either of aplurality of different known driving tools.

In accordance with the invention, the top face or crown of each of theplurality of angularly spaced head portions or segments 22, is in .theform of a compound angle by reason of the fact that its surface isinclined radially downwardly from its peripheral edge to its innercorner 24, located at or over the central cavity 20, and also inclinedangularly or circumferentially in opposite directions downwardly to andterminating at its adjacent slot defining edge whereby a line or ridge26, extending radially across the center of each of the segments 22,divides the same into two sloping triangular surfaces 28. Thus, thecompound angle formed on the top face or crown of each of the headportions 22, provides the means whereby a driving instrumentality isdeflected toward the center of the screw head 10, and into the cavity18, and at the same time oriented into alignment with either or both ofthe intersecting slots 12 and 14, upon being brought into contactingengagement with the top face or crown of the segments 22.

While the cavity 18 on the axis of the screw head 10, as best shown inFIGURE 3, merely provides clearance for pointed, winged driving tools,similar winged driving tools having a blunt end require little or noclearance. Thus, to accommodate all kinds of winge-d type screw drivers,the bottom of the slots 12 and 14 may slope slightly downwardly towardthe axis of the screw as at 30 and the depth thereof increased slightlywhereby the clearance cavity 18 may be dispensed with as clearly shownin FIGURE 4.

While the screw head shown is of the machine type, the recessed head 10is nevertheless adapted to be formed on other screws such as wood screwsand on |bolts, and even applied to the headless end of a common shaft orscrew shaft.

Thus, when a driving tool of the conventional blade type, cross bladetype, pointed winged type, or the square shank type, is brought intocontacting engagement with the screw head and not in the center thereof,the oppositely inclined top faces 28 of the segments 22, will deflectand orient the tool into the cavity 18, and into alignment with eitheror both of the intersecting slots 12 and 14. As aforesaid, the length ofthe screw head 10 and the diameter thereof is substantially of theFillister type depending of course upon the size of the screw threadwhich, -for the purpose of this invention, may vary from size 4 to 20,for example.

While the invention has been illustrated and described with respect tocertain embodiments thereof, it is to be expressly understood thatvarious changes and modifications may be made therein without departingfrom the inventive concept underlying the same. Therefore, the inventionis not to be limited except as is necessitated by the prior art and thescope of the appended claims.

What is claimed is:

1. A screw head of substantial length and uniform diameter having across-slotted driving recess centrally thereof forming a plurality ofdiametrically opposite triangular segments, each of said segmentspresenting a slightly inclined upstanding corner edge radially of andadjacent the screw head axis adapted to be engaged by a winged typedriving tool, each of said segments having a top face and a ridgeextending radially of said screw head and bisecting said segment, saidtop face being inclined downwardly radially toward the screw head axis.

and inclined downwardly in opposite directions lfrom said ridge so as todefine a pair of sloping triangular surfaces the terminal edges of whichdefine the cross-slots and Which are adapted to deflect a bladed drivingtool into alignment with the slots in said recess when brought intolcontacting engagement with said screw head.

2. A screw head as defined in claim 1 and further in- References Citedby the Examiner UNITED STATES PATENTS 7/1940 Fieg 85-45 6/ 1951 Stellin85-45 CARL W. TOMLIN, Primary Examiner.

M. PARSONS, JR., Assistant Examiner.

1. A SCREW HEAD OF SUBSTANTIAL LENGTH AND UNIFORM DIAMETER HAVING ACROSS-SLOTTED DRIVING RECESS CENTRALLY THEREOF FORMING A PLURALITY OFDIAMETRICALLY OPPOSITE TRIANGULAR SEGMENTS, EACH OF SAID SEGMENTSPRESENTING A SLIGHTLY INCLINED UPSTANTING CORNER EDGE RADIALLY OF ANDADJACENT THE SCREW HEAD AXIS ADAPTED TO BE ENGAGED BY A WINGED TYPEDRIVING TOOL, EACH OF SAID SEGMENTS HAVING A TOP FACE AND A RIDGEEXTENDING RADIALLY OF SAID SCREW HEAD AND BISECTING SAID SEGMENT, SAIDTOP FACE BEING INCLINED DOWNWARDLY RADIALLY TOWARD THE SCREW HEAD AXISAND INCLINED DOWNWARDLY IN OPPOSITE DIRECTIONS FROM SAID RIDGES SO AS TODEFINE A PAIR OF SLOPING TRIANGULAR SURFACES